1. Field of the Invention
The present invention relates to the booster structure of a jet engine. More specifically, the present invention relates to a jet engine booster structure having an improved pressure ratio in a single stage.
2. Description of the Related Art
In the prior art, there has been provided a booster 2xe2x80x2 downstream of a fan 1 in order to enhance the performance of a high bypass engine Exe2x80x2, as shown in FIG. 11.
As shown in FIG. 11, however, the booster 2xe2x80x2 is provided on the same shaft 3xe2x80x2 as the fan 1 and the number of revolutions of the booster 2xe2x80x2 is the same as that of the fan 1, whereby the circumferential speed of the moving blade 4 of the booster 2xe2x80x2 is, therefore, limited by that of the fan 1. Due to this, the circumferential speed of the moving blade 4 is extremely lower than a desired speed, so that a pressure ratio in a single stage becomes quite low. This results in a problem that the booster 2xe2x80x2 must consist of many stages so as to ensure a desired pressure ratio. Also, if the number of stages of the booster 2xe2x80x2 increases, the entire length of a compressor increases, resulting in a problem that the weight of an engine Exe2x80x2 increases. Furthermore, an increase in weight causes various problems.
The present invention has been made in view of the problems according to the prior art and has an object to provide a booster structure capable of obtaining a desired pressure ratio with fewer stages.
The jet engine booster structure according to the present invention is characterized in that a moving blade of a booster is a boundary layer control tandem moving blade.
In the jet engine booster structure according to the present invention, it is preferable that the inflow angle with a tandem moving blade lattice is within a range of 50 degrees to 70 degrees and that the efflux angle from the tandem moving blade lattice is within a range of 0 degree to 45 degrees. In addition, it is preferable that the deflection angle by a stator blade is within a range of 0 degree to 45 degrees.
Since the moving blade of the booster is the tandem moving blade in the booster structure according to the present invention, a pressure increase in a single stage is large and, therefore, a desired pressure increase can be attained with fewer stages.
Now, description will be given based on the mode of working the present invention with reference to the accompanying drawings. The present invention should, however, not be limited to the mode described herein.